It is known to use a pair of opposed pistons in each cylinder of an internal combustion engine and to convert the linear reciprocating motion of the pistons into a rotary motion of a drive shaft.
Such an engine having opposed pistons in each cylinder operating a crank shaft on opposite ends of the cylinder is shown in U.S. Pat. No. 876,870 (Gordon).
It is also known to use a pair of opposed pistons in each cylinder operating through a rack and pinion gear to convert the reciprocating movement to rotary motion and shown in U.S. Pat. No. 2,079,289 (Janicke) and U.S. Pat. No. 3,384,057 (Boone).